[masraum]

Originally Posted by daepp

IDK if this has already been covered, but:
- The submersible had no sonar, correct? I read that the mother ship had to guide it to the the wreck via short “text” messages.
- So I assume the mother ship had its own sonar to do so, right?
- And if the US Navy heard the implosion
Then how in the hell did the mother ship not hear and understand immediately that the Titan imploded?

I don't believe that the Navy's underwater listening devices are the same as SONAR. So even if the mothership had SONAR, that does not necessarily mean that they would have heard an implosion.

I suspect the current version is far removed from the version on wikipedia
https://en.wikipedia.org/wiki/SOSUS

what most folks think of is active SONAR. I suspect most active SONAR is automated, so the avg SONAR system echo-locates, but the system as purchased probably doesn't have a "I heard something under us implode" warning.
https://en.wikipedia.org/wiki/Sonar